According to Joaquin Villegas, MD, a family medicine physician with UTHealth Houston, “Supplementation with topical magnesium (such as spray, cream, or oils) has been used to help with muscle and joint pains, reduce migraine pain, and even help with anxiety and sleep, as well as boosting energy levels.
 
"What does spraying magnesium on your feet do?
Magnesium increases GABA in the body, a neurotransmitter that promotes sleep. We recommend keeping some magnesium oil or gel close to your bed so you can either spray or rub it onto your feet before sleep or if you wake. This calms the nervous system, so it can help you gain a deeper and more restorative sleep.